How To Migrate CentOS to AlmaLinux

In this tutorial, we will show you how to migrate CentOS to AlmaLinux. For those of you who didn’t know, AlmaLinux OS is an open-source, community-driven project that is built from the source code of Red Hat Enterprise Linux (RHEL). AlmaLinux is a completely binary compatible fork of RHEL 8 and it is built by the creators of the established CloudLinux OS.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you through the step-by-step installation AlmaLinux OS.

As usual, backup important data from your CentOS system before starting the upgrade process. Please note that the almalinux-deploy script is only to convert the latest CentOS 8.3 version to AlmaLinux 8.3. If you are running older versions like CentOS 7.x or 6.x, this script will not work.

Prerequisites

• A server running one of the following operating systems: AlmaLinux 8, or CentOS.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Migrate CentOS to AlmaLinux

Step 1. First, let’s start by ensuring your system is up-to-date.

sudo dnf update
sudo dnf install epel-release

Step 2. Migrate CentOS to AlmaLinux.

Now we download the CentOS 8 to AlmaLinux migration script:

curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh

Once the script is saved, give it the proper permission with the command:

chmod +x almalinux-deploy.sh

Then, run the script with the commands below:

sudo bash ./almalinux-deploy.sh

After the script performs a few initial checks, it will begin the process of removing, reinstalling, downgrading, and upgrading certain packages in order to synchronize the system with the current AlmaLinux release. The migration might actually take less time than the upgrade. Once the migration completes, reboot a second time and you’re done.

reboot

Once done, confirm that your CentOS 8 system was successfully converted to AlmaLinux 8:

$ cat /etc/os-release
NAME="AlmaLinux"
VERSION="8.3 (Purple Manul)"
ID="almalinux"
ID_LIKE="rhel centos fedora"
VERSION_ID="8.3"
PLATFORM_ID="platform:el8"
PRETTY_NAME="AlmaLinux 8.4 RC (Purple Manul)"
ANSI_COLOR="0;34"
CPE_NAME="cpe:/o:almalinux:almalinux:8.3:rc"
HOME_URL="https://almalinux.org/"
BUG_REPORT_URL="https://bugs.almalinux.org/"

ALMALINUX_MANTISBT_PROJECT="AlmaLinux-8"
ALMALINUX_MANTISBT_PROJECT_VERSION="8.3"

$ cat /etc/redhat-release
AlmaLinux release 8.3 RC (Purple Manul)

Congratulations! You have successfully migrated AlmaLinux. Thanks for using this tutorial to migrate CentOS to the AlmaLinux system. For additional help or useful information, we recommend you to check the official AlmaLinux website.